Discussion on Technical Measures and Selection Issues for Improving Mechanical Seals of Circular Arc Pumps

[1] To ensure the sealing degree of circular arc pumps in petrochemical plants, the use of mechanical sealing materials is necessary. In recent years, many new types of mechanical sealing materials have emerged, and the types and scope of mechanical sealing materials used in pump thermal mechanical equipment inside petrochemical plants are constantly expanding. For traditional mechanical sealing materials, metal and carbon graphite are used as basic materials, or ceramic based materials are used as friction pair materials. The sealing rings used in mechanical seals are composed of synthetic rubber and polytetrafluoroethylene materials. With the continuous acceleration of material technology development in our country, the application of high-performance sealing rings, lubricants and other new materials in pump mechanical seals is constantly increasing. With the application of new nanoscale composite materials, the performance of mechanical seal materials has been significantly improved. It is precisely because of the application of these new materials that the sealing degree of circular arc pumps has been improved

The fluid reflux mechanical seal technology mainly changes the flow path of the leaked fluid and transports it to the inside of the mechanical seal box to achieve the leakage prevention function of the entire mechanical equipment. Through the application of this technology, it is more convenient for the entire maintenance work and also has strong applicability and other advantages. Due to this advantage, this technology is often used in high-temperature and high-pressure environments for sealing work

The non-contact mechanical seal technology is mainly based on the dynamic pressure or economic pressure generated by the fluid, forming a good isolation effect throughout the entire sealing surface, ensuring the overall effect of the non-contact mechanical seal. Through the application of this technology, it has good durability and sealing performance, and its performance is very obvious in the production and processing work of aerospace, energy and petrochemical in China

[2] Discussion on Selection of Shaft Seals for Circular Arc Gear Pumps

The selection of shaft seals for circular arc gear pumps includes three commonly used design schemes, namely packing, double end face mechanical seal, and single end face mechanical seal structure.

. The selection of shaft seal for circular arc gear pump is an important link to ensure the sealing performance of the pump, which is related to the performance of the pump

The design schemes for single end mechanical seals and double end mechanical seals have complex production processes and require high costs. Therefore, the prices of these two types of shaft seal products are also high. However, the shaft seal effect of using these two types of shaft seal products is very good, with few leakage phenomena, and they have high reliability in the production process of chemical products

The production process of shaft seal products with packing sealing structure is simple, the process flow is not complex, and the cost is very low compared to others. However, the shaft seal effect is not good, and leakage often occurs. It is basically not suitable for the leakage requirements of fine chemical products. Therefore, it can only be used in some low-cost energy transportation shaft seal processes with low leakage requirements

When selecting mechanical seal structures, it is also necessary to divide them into two types: balanced and unbalanced. The balanced mechanical seal structure can reduce the pressure reaching the sealing end face, so this structure is suitable for environments with high liquid pressure for conveying. The non-equilibrium mechanical seal structure is suitable for environments with lower liquid medium pressure during transportation